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- N. G. HERRBSHOIP.

VALVE GEAR FORSTEAM ENGINES.

No. 280,311; Patented June`26,-1883.f

ENI'TRD STATES HNA'THANIRL e. HERRRSHOFF, or RRIsTOL, RHODE IsLAND, AssIeNoR To I THR HnRRRsROFF MANUFACTURING coMrAN Y, or RHODE ISLAND.

vALvi-:meEAR ,FOR STEAM-Encinas.'

SPECIFICATION forming part of Letters Patent No. 280,311, dated .Time 26 1883.

' 4Appiicfninn mea March 1e, inea. (Nmoaqili To gir/ZZ whom) it may concern.-

Be it known that I, NATHANIEL G. HERRE- sHoFF, of Bristol, in the county of Bristol and State of Rhode Island` have invented certain v5 new and useful Improvements in Valve-Gear for Steam-Engines, of which the following is a specification. i

I allow, by ample annular ports extending around the cylinder, unusually liberal passages 1o for the admission and escape of the steam,

adapting the engine to work efficiently at very high speeds.

The invention consists in the detailsof the Y. mechanism fully Set forth below. It is intend- 15 ed more especially forsmall swift Steamers with screw-propellers, but may be of advantage in a great variety of situations.

The following is a description of what I eonsider the best means of carrying out the invenzo'tion. v

The accompanying drawings form a part of this specification.

Figure 1` is a central Vertical section through the cylinder of an upright engine. Fig. 2 is 2 5 a horizontal..section on the line x :v in 1. The piston is not sectioned, but drawn in plan. Fig. 3 is a plan View of certain portions on a smaller scale, and Fig. 4 is a vertical section ofthe same. Fig. 5 is a general perspective .3o view of the working parts of the engine.

Si milarletters ofrefercnce indicatelike parts in all the figures.

.Thedrawings show the novel parts with so much of the ordinary parts as is necessary to 3 5 show their relation thereto.

I linish at both ends ofthe cylinder, on the ,exterior thereof, an even surface, with a port at each end through such surface, extending quite around, except that it is broken by bridges 4o to maintain the continuity ot' the metal. An annular valve incloses the cylinder at each end, fitting steanrtight upon the cylindrical seats thus provided. A rigid cylindrical casing is fitted exterior' to the valve at each end, a tight 4 5 joint heilig maintained therewith by apackingring. vThe annular valve at one end is rigidly connected to the annular val ve at the other end. The whole is made in sections. A spring-packing is interposed between the sectionsof the 5oV valve and the sections of the packing-ring.

There are many valvestems as there are sections ofthe valve-ring. Means areprovided -B are connected by rigid lattice-work.

for Working the whole uniformly, and to allow fonslight mal-adiustmentsfand variations ot' expansion, 81e. 55

Referring to the iigures, A-is the cylinder. and A the external concentric casing. B B are the annular valves, and C the packing-rin therefor. D are the springs, interposed between C and B. The two annular valves B 6o The valves and the connecting-lattice are divided longitudinally along four lines, so as to make foursections. vThe packing-rings C are correspondingly divided, but arranged so that they 6 5 break joints with the valves. 4 There are four valve-Steins, B-one valve-stem for each section ofthe valve. The valve-stems are attached by twos to a pair of levers or eveners, E, which turn' on pins G, set in a large ring, G, which 7o is moved up and down by two separate but equal link-motions attached to the trunnionsA G2. The ring G is made o'fstout tubing, so as to be stiff with little weight, andis guided by bearings G3, which embrace smoothly-iinished 7 5 upright posts A of the framing which forms part of the supporting-franling for the cylinf ders, as will be readily understood. Iemploy two setsof what is iknown as the Stevenson link-motion, or, more briefly, 8O link-motion. H is one of the links of the style sometimes known as single or solidthat is, not slotted, but curved to the proper radius, and nicely finished. It is rocked by eccentric-rods l, leading each from a separate 85 leccentric set on the main shaftas will be understood. It is shifted by a lilik, J. 'There are two of these links H, and two of the links .Lactuated by two' arms, K', from a' shaft, K, mounted in suitable fixed bearings, and turned 9o by a hand-level', K, equipped with dogs for 'engaging with notches on a quadrant, in the -ordinary long-approved manner.

The turn ing` of the single lever K2 shifts both links H.

The eveners E perform an vimportanti fune- 95 tion in equalizing the action ot' the two lin/kmotions on the four valve-stems, and consequently on all parts ofthe val ve under all conditions. The sections ot' thevalve B, having a length equal to the working part of the cyl 10o inder, andbeing well tied together by the sections of the packing-rings C, work practically as one, and open and close the annular ports uniformly all around.

The two sets of valve-gear, Vone for each ofA the trunnions G2, should be equal; but in case of any mal-adjustment or inequality, the ring G, with its levers H, serves, like the gimbalring of a compass, to allow for the inequality,

so that all the valve-stems will be actuated equally. With any reasonably good work the action of the two sets of valve-gearwill be approximately equal. 'It is therefore necessary xo to allow only a small amount of rocking to the levers I-I. I have arranged the levers so that when they have rocked a little way one end or the other will bear iirmly on the' ring G, thus preventing anyfurther rocking.. In case of the breakage of the comiection of one of theA valve-stems, or some analogous failure of a part, the engine may continue to work, though'im perfectly, by the valve being worked by the other three stems. The limited amount of the,

2o rocking is of advantage in facilitating the work under such conditions.

The making of the valves B and packingring C in sections allows themto open and close a little. This accommodates any varia- 2 5 tion in expansion and contraction of the valves and cylinder. It also performs an important function when there is water in the cylinder, i which must find avent "as the piston approaches the end of the cylinder, after the'valve has closed, and has commenced to cushion the exhaust. If the valves were continuous annular rings, there would be no vent. Being sections, they may yield by the compression of the springs D, and allow a liberal vent all around for the discharge of the water. Each joint betweenrthe sections of the valves yB isarranged to come on a bridge dividing-the ports, so that there is no leakage of steam into or out of the cylinder through such joints. rEhe joints may be formed' in any ordinary or approved manner, and guarded by a tongue or coveringplate against the passage of steam vertically across the valve. The packing-ringsA C are similarly equipped.

`B extending around the cylinder A, as shown,

Modiiicationsmay be made in the forms andf.- 45 j proportions of the details. -Parts may be used 'si with some' success without the whole".v VAInstead ofspring-packing, steam.-packingAmayfmiused.'

I claim as my inventionl. The annular valves B, made in sections, adapted to allow the valve to expand and contract, in combination with a cylinder, A, hav.-

ing annular ports, with" bridges; the 'jointsfin,l e

thereto, the valves B for the two ends rigidly A united, and formed in sections, as shown, in

combination with each other and with thepacking-rin' operation, as herein speciied.- u

3. In a steam-engine, the twol link'sH H, actuated independently, but similarly, in com bination with each other, and with suitable c'onnections to annular valves B B, working asY shown, relatively to a. single cylinder, A, having annular ports, substantially as herein' specified. 4. In a steam-engine having annlarvalves the four or more valve-stems B', connected gimbal-wise, so that the actuating force is applied .equally to all, as herein specified.

5. The rocking levers or eveners E E, `in* combination with thel ring .G and valve-stems B', arranged to limit the extent of the rocking. motion,fsubstantially as and for the purpose herein specied.v

In testimony whereoilIhave hereunto set my 8o hand, at Bristol, Rhode Island, this 9th day of March, 1882, inthe presence of two'subscribing witnesses.

NATHL. G.- HERRESHOFF.

VVitnessesz Y C. H. KINYoN, J. F. SMITH.

se V

gs C and springs D,arranged for jointf p v 

